U.S. patent number 6,844,912 [Application Number 10/296,825] was granted by the patent office on 2005-01-18 for optical system for the rotation of images taken by a film camera about the optical axis.
This patent grant is currently assigned to Arnold & Richter Cine Technik GmbH & Co. Betriebs KG. Invention is credited to Pavel Filous, Michael Haubmann, Walter Trauninger.
United States Patent |
6,844,912 |
Filous , et al. |
January 18, 2005 |
Optical system for the rotation of images taken by a film camera
about the optical axis
Abstract
The invention relates to an optical system for the rotation of
images taken by a film camera about an optical axis, having a
controller device for the rotation of images with an adjusting
motor and a position sensor for recording the rotation angle of the
image-rotating optical system. In addition, the possibility of
displacing the optical system in at least one axial direction is
provided.
Inventors: |
Filous; Pavel (Guntramedorf,
AT), Trauninger; Walter (Lamb im Wald, AT),
Haubmann; Michael (Vienna, AT) |
Assignee: |
Arnold & Richter Cine Technik
GmbH & Co. Betriebs KG (Munich, DE)
|
Family
ID: |
7644457 |
Appl.
No.: |
10/296,825 |
Filed: |
November 25, 2002 |
PCT
Filed: |
May 16, 2001 |
PCT No.: |
PCT/DE01/01909 |
371(c)(1),(2),(4) Date: |
November 25, 2002 |
PCT
Pub. No.: |
WO01/90786 |
PCT
Pub. Date: |
November 29, 2001 |
Foreign Application Priority Data
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May 23, 2000 [DE] |
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100 27 371 |
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Current U.S.
Class: |
352/105;
359/625 |
Current CPC
Class: |
G03B
19/20 (20130101); G02B 27/642 (20130101) |
Current International
Class: |
G02B
27/64 (20060101); G03B 19/20 (20060101); G03B
19/00 (20060101); G03B 041/02 (); G02B
027/10 () |
Field of
Search: |
;352/105,106,110
;359/625 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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24 36 230 |
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Feb 1975 |
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DE |
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30 46 626 |
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Jul 1982 |
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DE |
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32 45 477 |
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Jun 1983 |
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DE |
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195 05 944 |
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Apr 1996 |
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DE |
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09145541 |
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Jun 1997 |
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JP |
|
Other References
International Search Report of PCT/DE01/01909, dated Dec. 11, 2001.
.
International Preliminary Examination Report of PCT/DE01/01909,
dated Sep. 3, 2002. .
English Translation of International Preliminary Examination Report
of PCT/DE01/01909, dated Sep. 3, 2002..
|
Primary Examiner: Nguyen; Judy
Assistant Examiner: Smith; Arthur A
Attorney, Agent or Firm: Christie, Parker and Hale, LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a National Phase Patent Application of
International Application Number PCT/DE01/01909, filed on May 16,
2001, which claims priority of German Patent Application Number 100
27 371.8, filed May 23, 2000
Claims
What is claimed is:
1. An optical system for the rotation of images taken by a film
camera about an optical axis, the system comprising: a device
controlling the rotation of the images taken and having an
adjusting motor and a position sensor which detects the rotation
angle of the optical system; and a tube containing, a rotatably
mounted optical element for rotating the images taken, an iris
aperture, and a relay optic or double Gauss lens for converging
optical beams of the images taken towards the iris aperture and
diverging the optical beams towards a fixed prism; wherein the
adjusting motor is mounted in the tube and comprises a ring-shaped
drive motor mounted about the rotatably mounted optical element of
the optical system for rotating the images taken, and wherein the
position sensor detects a rotational angle of the rotatably mounted
optical element and is fixed on the tube.
2. The optical system according to claim 1 wherein the recorded
images continuously rotate about the optical axis.
3. The optical system according to claim 1 or 2 wherein the
rotatably mounted optical element is displaceable in either or both
the direction of the optical axis and a direction perpendicular
thereto.
4. The optical system according to claim 1, wherein the rotatably
mounted optical element comprises one of a rotatable prism and a
rotatable mirror assembly.
5. The optical system according to claim 4 wherein the rotatable
prism is a Schmidt Pechan prism.
6. The optical system according to claim 1 wherein at least one of
a field lens, a field lens system, the rotatable prism, the
rotatable mirror assembly, a transmission lens, a fixed prism and a
mirror assembly are provided in the direction of a recording beam
path.
7. The optical system according to claim 6 wherein the transmission
lens comprises a relay optic or a double Gauss lens.
8. The optical system according to claim 1 wherein the optical
system is mounted between a lens carrier of a camera housing and a
recording lens of the film camera.
9. The optical system according to claim 1 comprising a front and
rear fastening flange for connecting the optical system to a
recording lens and to a lens carrier of a camera housing.
10. The optical system according to claim 1 wherein a rear
fastening flange of the optical system is arranged so that in the
optical system is connected to a lens carrier and a fixed prism is
mounted at least in part inside a camera housing.
11. The optical system according to claim 1 wherein an iris
aperture is mounted in the optical system between a transmission
lens and a fixed prism and can be operated from a housing side of
the optical system.
12. The optical system according to claim 1 further comprising an
adjusting device which adjusts at least part of the optical
elements of the optical system.
13. The optical system according to claim 12 wherein the device
adjusting at least part of the optical elements of the optical
system has means for correcting picture errors.
14. The optical system according to claim 1 wherein a field lens or
a field lens system is arranged and fixed so that the field lens or
at least a part of the field lens system can be exchanged.
15. The optical system according to claim 1 wherein the rotatably
mounted optical element is suspended through a cardan fixing in a
housing of the optical system and is adjustable in at least two
planes.
16. An optical system for the rotation of images taken by a film
camera about an optical axis, the system comprising: a tube
containing a rotatably mounted optical element for rotating the
images taken, wherein the rotatably mounted optical element is
fixed in a prism chair which is mounted in a prism holder to swivel
about a first axis, and wherein the prism holder is mounted in a
prism shaft connected to a ring-shaped drive motor to swivel about
a second axis; a device controlling the rotation of the images
taken and having an adjusting motor and a position sensor which
detects the rotation angle of the optical system wherein the
adjusting motor is mounted in the tube and comprises a ring-shaped
drive motor mounted about the rotatably mounted optical element of
the optical system for rotating the images taken, and wherein the
position sensor detects a rotational angle of the rotatably mounted
optical element and is fixed on the tube.
17. The optical system according to claim 16 wherein the prism
shaft is mounted inside a distance sleeve for the bearing of the
rotatably mounted optical element, wherein the distance sleeve is
mounted inside a tube and wherein the tube is enclosed by a cover
of the housing of the optical system.
18. The optical system according to claim 16 or 17, wherein the
first and second axis are defined by bolts wherein the bolts
defining the first axis are arranged diametrically opposite one
another, are mounted rotatably in the prism shaft and are connected
to the prism holder and wherein the bolts defining the second axis
are arranged diametrically relative to each other and perpendicular
to the bolts defining the first axis and are mounted in the prism
holder and are connected to the prism chair.
19. The optical system according to claim 18, wherein an opening
for adjusting the bolts is provided in the housing of the optical
system or in the tube and in the prism shaft.
20. The optical system according to claim 1 or 16 wherein a housing
of the optical system is connected through a connecting element to
iris rods fixed on a camera housing of the film camera.
21. The optical system according to claim 20 wherein the connecting
element comprises a control electronics unit connected to the
position sensor and the ring-shaped drive motor.
22. The optical system according to claim 16 wherein the second
axis is perpendicular to the first axis.
23. The optical system according to claim 16 wherein the rotatably
mounted optical element is suspended through a cardan fixing in a
housing of the optical system and is adjustable in at least two
planes.
24. An optical system for the rotation of images taken by a film
camera about an optical axis, the system comprising: a film camera
having a film transport mechanism for intermittently moving the
film; a tube containing an optical element for rotating the images
taken; and a device controlling the rotation of the images taken
and having an adjusting motor and a position sensor which detects
the rotation angle of the optical system, said adjusting motor
being mounted in the tube and comprising a ring-shaped drive motor
mounted about said optical element for rotating the images taken,
wherein said position sensor detects a rotational angle of the
optical element and is fixed on the tube, and wherein rotation of
the optical system is synchronized with the film transport.
25. The optical system according to claim 24 wherein the rotation
of the optical system takes place in a transport phase of the
moving film.
26. The optical system according to claim 24 or 25 wherein during a
transport phase of the moving film a release signal is sent to a
control electronics unit to control the adjusting motor.
Description
FIELD OF THE INVENTION
The invention relates to an optical system and more specifically to
an optical system for the rotation of images taken by a film camera
about an optical axis.
BACKGROUND OF THE INVENTION
From DE 24 36 230 A1 an optical system is known for the rotation of
images in a recording lens system for television cameras, movie
film cameras and photographic cameras. The optical system contains
a prism which serves for the rotation of the image and which is
mounted between a forward lens and a rear lens of a relay-lens
system, as well as a field lens which is mounted on a first
focusing plane on which an image is created through an objective
lens. The field lens has a focal distance such that the pupil of
the relay-lens system conjugated to the opening of the objective
lens can be arranged in the centre point of the beam path of the
prism which is serving for the rotation of the image.
From DE 3245 477 A1 an optical system is known for image rotation
which has a projection lens system for creating an image in a
predetermined plane, a prism for image rotation rotatable about the
optical axis of the projection lens system, and a slit element for
screening light which is mounted between the projection lens system
and the prism and which is rotatable with the rotation of the prism
about the optical axis.
The use of an optical system of this kind for image rotation in
conjunction with a film camera means that when an image rotation is
required it is no longer necessary to rotate the entire film camera
about the optical axis so that the film camera can be operated as
normal and the eyepiece as well as all operating elements of the
film camera remain in their standard position. The use of standard
lenses and standard accessories is thereby guaranteed and these can
be fitted on hand-held systems or on systems fixed to the body of
the cameraman.
From U.S. Pat. No. 4,427,269 a method and device are known for
automatically compensating the image rotation through an
articulated optical system which consists of members with lenses
for the optical representation as well as articulated joints with
mirrors or prisms for deflecting the beam path. In order to
compensate the image rotation when the articulated optical system
rotates a signal is generated whose polarity is dependent on the
direction of rotation of the image produced in an observation plane
relative to an object. From this signal a compensation element
mounted in the beam path of the articulated optical system is
controlled and actuated until the signal disappears. The
compensation element consists of an optical element for image
rotation formed as a Dove prism and mounted inside one tube of the
several interconnected tubes of the articulated optical system and
connected through gearing to a motor mounted outside of the tube
and controlled by a servo booster.
The servo booster receives a signal from a signal processor which
is connected to a sensor mounted on the observation plane and on
which an image is depicted of markings arranged inside or outside
an intermediate image. If this marking deviates from a
predetermined neutral position then the sensor produces a signal
which leads through the signal processor and the servo booster to
control the motor which through the gearing turns the optical
element for compensating the image rotation until the image marking
is again located in the neutral position.
From U.S. Pat. No. 5,677,763 an optical measuring and viewing
device is known with which physical and optical characteristics of
an object are measured by means of a device for image rotation
which can consist of a Dove prism, a Pechan prism or a mirror
assembly and the measured beams are sent to a one-dimensional CCD
element. The image-rotating optical element is mounted inside a
tube which is supported through ball bearings on a housing on which
a drive motor is fixed which is connected through a drive belt to
the image-rotating optical element. Additional optical elements
such as planar concave lenses, aperture and a planar convex lens
are mounted outside of the tube but inside the housing of the
optical measuring and viewing device and are fixedly connected to
same.
The aforementioned U.S. Pat. No. 4,427,269 and U.S. Pat. No.
5,677,763 specification are directed more particularly to the needs
for compensating image rotations in an articulated optical system
and for measuring the outlines of an object. The demands on an
optical system for rotating recorded images of a film camera differ
quite considerably from this.
One requirement of an optical system of a film camera is the light
intensity of the optical system used, for only with an optical
system having a high light intensity can satisfactory film shots be
produced even with high-speed films and under unfavourable lighting
conditions. A further requirement for an optical system of a film
camera lies in its simple handling which is also to include minimal
size and easy assembly and dismantling. Furthermore in order to
produce special effects when filming, extremely high dynamics of
the optical system have to be guaranteed so that inter alia the
so-called "stroboscopic effects" can be achieved, i.e. special
effects which are connected with a sudden change of the position of
the horizon line. Extremely high dynamics of this kind require
special mechanical measures in order to keep the moved masses
slight and to ensure a direct force or torque transfer.
SUMMARY OF THE INVENTION
The object of the invention is therefore to integrate an
image-rotating optical system in the picture system of a film
camera without reducing the optical performance of the picture
system, which has an extremely fine adjustment and very high
optical system dynamics, and which takes up less structural space
and ensures minimal noise development.
The solution according to the invention makes it possible to
integrate an image-rotating optical system into the picture system
of a film camera without reducing the optical performance of the
picture system and which has a highly accurate adjustment and very
high optical system dynamics which takes up minimal structural
space, ensures a high operating comfort and high adjusting speeds
during image rotation with a minimal level of noise.
Through the direct rigid connection of a ring-shaped drive motor
and a position sensor with the image-rotating optical system no
mechanical play occurs and due to the absence of a mechanical
gearing means the noise level is significantly reduced. Furthermore
the structural space required is less than in an arrangement with
drive motors arranged externally and eccentrically relative to the
optical system. Through the direct installation of a ring-shaped
drive motor about the image-rotating optical element no external
and eccentric forces are introduced into the optical system which
could lead to a reduction in the optical performance, for example
preventing centering of the optical system.
In particular the image-rotating optical system is suitable for
continuously rotating pictures taken about the optical axis.
An advantageous development of the solution according to the
invention is characterised in that the rotationally mounted optical
element consists of a rotatable prism, preferably a Schmidt-Pechan
prism and/or a mirror assembly.
The image rotation and/or alignment of the images taken can take
place selectively through a prism or through several mirrors
aligned corresponding to each other and rotatable about the optical
axis, or through a combination of rotatable prisms and rotatable
mirrors.
In particular the optical system has in the direction of the
recording beam path a field lens or a field lens system, the
rotatable prism and/or the rotatable mirror assembly, a
transmission lens and a fixed prism or a fixed mirror assembly.
Furthermore the transmission lens can include a relay optic or a
double Gauss lens.
A further development of the solution according to the invention is
characterised in that the optical system for the rotation of images
taken about the optical axis is mounted between a lens carrier and
a recording lens of the film camera wherein the optical system for
the rotation of the recorded images about the optical axis has a
forward and rear fastening flange for connecting the optical system
to the recording lens and to the lens carrier of the camera
housing.
By arranging the rear fastening flange of the optical system
between the transmission lens and the fixed prism it is possible to
arrange the fixed prism at least in part inside the camera housing
so that a corresponding shortening and integration of the optical
system in the film camera is possible.
In an advantageous development of the solution according to the
invention an iris aperture is mounted in the image-rotating optical
system between the transmission lens and the fixed prism and can be
operated from the housing side of the optical system.
By means of a device adjusting at least a part of the optical
elements of the image-rotating optical system it is possible to
adapt the image-rotating optical system to different recording
lenses so that lenses can also be used whose exit pupils have pupil
positions which differ strongly from each other, such as for
example zoom lenses.
Since in particular zoom lenses have the property that in most
embodiments the exit pupil position changes severely when changing
the focal width, it is advantageous to carry out an adaptation of
the optical system to different focal widths. This can be
undertaken during operation for example through a corresponding
adaptation of a field lens system.
An adjusting device can also include for example a field lens or a
field lens system being mounted and fixed in the optical system so
that the field lens or at least a part of the field lens system can
preferably be exchanged from the side of the front fastening
flange.
With an interchangeable field lens or a part-interchangeable field
lens system there is the possibility of making use of lenses with
sharply differing pupil positions outside of the operation of the
film camera.
A further adjusting device consists in the rotatable prism or the
rotatable mirror assembly suspended with a cardan joint in the
housing of the optical system and adjustable in at least two
planes. In addition to tilting, the rotatable prism or the
rotatable mirror assembly can be displaced in at least one axial
direction, i.e. in the direction of the optical axis and/or
perpendicular thereto.
For this purpose the rotatable prism is fixed in a prism chair
which is mounted in a prism holder for swivel movement about a
first axis, and the prism holder is mounted in a prism shaft
connected to the ring-shaped drive motor for swivel movement about
a second axis which is preferably arranged perpendicular to the
first axis. The prism shaft can be disposed inside a distance
sleeve for the bearing of the rotatable prism whilst the distance
sleeve is mounted inside a tube and the tube is surrounded by a
cover of the housing of the optical system.
Preferably the first and second axis consist of bolts wherein the
bolts forming the first axis are arranged diametric relative to
each other, are mounted rotatable in the prism shaft and are
connected to the prism holder, whilst the bolts forming the second
axis are arranged diametric relative to each other and are mounted
perpendicular to the bolts of the first axis and are mounted in the
prism holder and connected to the prism chair.
In order to adjust the bolts and thus the position of the rotatable
prism an opening for adjusting the bolts is disposed in the housing
of the optical system or in the tube and in the prism shaft.
A further advantageous development of the solution according to the
invention is characterised in that the housing of the optical
system is connected through a connecting element to support tubes
or rods fixed on the camera housing wherein the connecting element
contains in particular a control electronics unit connected to the
signal sensor and the ring-shaped drive motor.
By connecting the control electronics for evaluating the position
sensor signals and for controlling the ring-shaped control motor of
the optical system for the image rotation to the control
electronics of the film camera it is in particular possible to
synchronise the rotation of the image-rotating optical system with
the film transport. In particular the rotation of the
image-rotating optical system can be carried out in the transport
phase of the moving film.
By using a motorised drive for rotating the image-rotating optical
system it is possible not only to reach very high adjusting speeds
but also adjusting movements synchronised with the film camera in
the transport phase of the moving film. Therefore it is possible to
undertake a change in the horizon line of the film camera between
the exposure of successive individual images whereby the direct
installation of the drive in coaxial form means that no external
and eccentric forces are introduced into the system which could
lead to a reduction in the optical performance.
In particular the control electronics of the film camera can issue
a release signal to the control electronics during the transport
phase of the moving film to control the adjusting motor of the
image-rotating optical system so that an image rotation is always
then possible when the recording beam path is interrupted during
the transport phase of the moving film.
BRIEF DESCRIPTION OF THE DRAWINGS
The idea on which the invention is based will now be explained in
further detail with reference to the embodiment illustrated in the
drawing in which:
FIG. 1 shows a diagrammatic view of the basic construction of an
image-rotating optical system mounted between a recording lens and
a film camera;
FIG. 2 shows a detailed view of the arrangement according to FIG.
1;
FIG. 3 shows a detailed view of an image-rotating optical
system;
FIG. 4 shows a section through the optical system according to FIG.
3 along the line IV--IV, and
FIG. 5 shows a section through the image-rotating optical system
according to FIG. 3 along the line V--V.
DETAILED DESCRIPTION
The basic construction of an image-rotating optical system 3
mounted between a recording lens 1 and a film camera 2 and shown
diagrammatically in FIG. 1 has in the direction of the recording
beam path behind the recording lens 1 a field lens which in a
preferred embodiment according to FIGS. 2 and 3 is designed as a
field lens parcel.
In the recording beam direction behind the field lens there is a
rotatable prism 5 which can consist for example of a Schmidt-Pechan
prism. The rotatable prism 5 is connected to an adjusting motor 8
which consists of a ring-shaped drive motor for the rotation of the
rotatable prism 5 about the optical axis A. In order to detect the
relevant rotational angle of the rotatable prism 5 relative to a
reference position there is a position sensor 9 which consists for
example of an optoelectronic position sensor with a high resolution
of the angle degrees to be detected.
As an alternative to the rotatable prism or in combination with a
rotatable prism it is possible to use a mirror assembly with
several mirrors aligned relative to each other and arranged in a
corresponding rotational device.
In addition to the rotation or tilting of the rotatable prism or
the rotatable mirror assembly there is also the possibility of
displacing the rotatable optical system in at least one axial
direction, i.e. perpendicular to the optical axis or in the
direction of the optical axis.
In the recording beam direction behind the rotatable prism 5 or the
rotatable mirror assembly there is a relay optic 6 which can
include for example of a double Gauss lens. The closure of the
image-rotating optical system 3 is formed by a fixed prism 7, for
example likewise a Schmidt-Pechan prism. Inside the camera housing
20 there is a rotatable mirror aperture 22 which interrupts the
recording beam path during the film transport so that the
individual film images of the moving film are moved intermittently
to a picture window 26 which is located in the film plane FE and
are released for exposure after release of the recording beam path
through a cut-out section of the mirror aperture 22.
As can be seen from the diagrammatic illustration in FIG. 1 the
image-rotating optical system 3 is connected to a lens carrier 21
of the camera housing 20 of a film camera 2 so that the fixed prism
7 projects into the camera housing 20 of the film camera 2 where it
is restricted in regards to its arrangement through the rotating
mirror aperture 22 of the film camera 2.
As can be seen from the detailed illustrated in FIG. 2 the camera
housing 20 of the film camera 2 contains a lens carrier 21 for
fixing replacement lenses or image-rotating optical system 3 and in
the optical axis of the recording lens 1 there is a picture window
26 set in the camera housing 20 past which a moving film 25 is
intermittently moved. For this purpose the film camera 2 contains a
film transport mechanism 24 with a gripper switch mechanism as well
as toothed rollers for unwinding and feeding back the film 25 in a
camera cassette which is to be connected to the camera housing
20.
A rotating mirror aperture 22, connected to the film transport
mechanism through an aperture motor or gearing and driven by same,
releases the film recording beam path entering through the
recording lens 1 and image-rotating optical system 3 periodically
as a film exposure beam path for exposure of a film image of the
film 25 standing in the picture window 26, or reflects the film
recording beam path during the film transport as a reflected beam
path to a beam divider from which a viewfinder beam path branches
off to a viewfinder eyepiece 23 and where necessary a video beam
path branches off to a video recording appliance or CCD-video chip
or to other image viewing or processing devices connected to the
film camera.
The beam path S entered in the basic construction of the optical
system 3 according to FIG. 1 shows that the recording lens 1
focuses an image to be taken in a first plane on which a field lens
4 or the focusing plane of a field lens packet is mounted in order
to converge the beams coming from the recording lens 1. By means of
the rotatable prism 5 which is mounted behind the field lens 4 the
beams are brought into the relevant desired image position and
converged in the double Gauss lens 6 towards an iris aperture 10
and then passed on diverging to the fixed prism 7 from where an
image is projected in the plane of the picture window 26 when the
cut-out section of the rotating mirror aperture 22 releases the
recording beam path for taking an image on the movie film 25.
In the detailed illustration according to FIG. 2 as well as in the
enlarged view of the image-rotating optical system 3 according to
FIG. 3 it can be seen that the recording lens 1 is connected
through a front fastening flange 31 to the image-rotating optical
system 3 which is connected through a rear fastening flange 32 to
the lens carrier 21 of the film camera 2.
Of the field lens packet 4 the front lenses combined together with
a holder 40 can be exchanged for different groups of recording
lenses and can be adapted to different beam paths. Furthermore the
interchangeable field lenses adapt to the exit pupil positions of
the different recording lenses and ensure an optimum light
distribution since different recording lenses can lead to
considerable brightness differences over the image surface and thus
to a considerable loss of quality.
The front lenses of the field lens packet 4 combined together with
the holder 40 can be removed by means of a tool 13 from the front
side of the image-rotating optical system 3 and replaced by a lens
system of a different refraction. The ease of interchanging the
front lenses of the field lens packet 4 means that it is easily
possible to adapt to the exit pupil positions of different
recording lens with optimum light distribution in particular as a
result of the easy access to the front lenses from the front side
of the image-rotating optical system 3.
Inside a tube 30 of the image-rotating optical system 3 there is a
ring-shaped drive motor 8 which is connected directly to the
mounting of the rotatable prism 5. A position sensor 9 detects the
relevant position of the rotatable prism 5 in relation to a
reference angle position and sends the relevant position to an
electronics unit 12 which is mounted in a connecting element 11
which can be connected to support rods or tubes 27 which are fixed
on the camera housing 20. The connecting element 11 thereby exerts
at the same time a supporting and fixing function for the optical
system 3. Control signals are sent from a control electronics unit
12 to the ring-shaped drive motor 8 for rotating the rotatable
prism 5.
By connecting the control electronics unit 12 to the camera
electronics unit the adjusting movements of the rotatable prism 5
are synchronised with the transport of the recording film 25. This
synchronisation is carried out so that during the film transport,
that is in the phase in which the revolving mirror aperture 22
covers the recording beam path to the picture window 26 and the
film is transported intermittently on by one image by means of the
film transport mechanism 24, an adjusting movement of the rotatable
prism 5 and thus a change of the horizon line of the recorded
images are carried out.
Before the end of the film transport and release of the film
picture to be exposed through the rotating mirror aperture 22 the
adjusting movement of the rotatable prism 5 is also terminated so
that for successive individual images a corresponding change of a
horizon line can be carried out. As a result of the motorised
adjustment of the rotatable prism 5 very high adjusting speeds can
be reached so that in many cases an adjustment of the horizon line
of the rotatable prism 5 can be undertaken within one individual
transport step of the moving film 25.
FIG. 4 shows in a section along the line IV--IV according to FIG. 3
the arrangement of the ring-shaped drive motor 8 inside the tube 30
of the image-rotating optical system 3, as well as a motor
connection 80 of the ring-shaped drive motor 8 which is connected
through a prism shaft 50 to the rotatable prism 5 (FIG. 5) and is
supported relative to the tube 30 through a motor holder 81.
By using a ring-shaped drive motor 8 it is thereby ensured that no
external eccentric forces are introduced into the image-rotating
optical system 3 which could lead to a reduction in the optical
performance of the image-rotating optical system 3. Through the
rigid connection between the ring-shaped drive motor 8 and the
rotatable prism 5 as well as through the fixed arrangement of the
position sensor 9 in the tube of the image-rotating optical system
3 no mechanical play occurs in the drive so that a highly accurate
adjusting of the horizon line can be achieved by means of the
image-rotating optical system 3.
Since furthermore no mechanical gearing is required for
transferring the rotational movement from the adjusting motor to
the rotatable prism 5 a minimum noise level can be reached. Since
the ring-shaped drive motor can be mounted without problem inside
the tube 30 of the image-rotating optical system 3 the structural
space required for the rotation of the rotatable prism 5 is minimal
and clearly less than with external drives.
In order to be able to centre the rotatable prism 5 in an optimum
manner it is suspended in three axes to form a cardan-type bearing.
This cardan-type suspension enables the rotatable prism 5 to tilt
vertically and horizontally and to be adjusted vertically in
relation to the recording beam path, i.e. to undertake in addition
to a tilting movement also a displacement movement in at least one
axial direction--in the direction of the Y-axis according to FIG.
1. This cardan-type suspension of the rotatable prism 5 can be seen
from the sectional view of FIG. 5 which shows a section through the
image-rotating optical system 3 along the line V--V of FIG. 3.
The rotatable prism 5 is fixed in a prism chair 52 whose position
can be changed relative to a prism holder 51 by means of two
adjusting bolts 54, 56. The position of the prism holder 51 is in
turn variable relative to a prism shaft 50 which is supported
through a distance sleeve 34 relative to the tube 30 of the
image-rotating optical system.
For tilting and displacing the rotatable prism 5 the tube 30 has an
adjusting opening 35 and in the prism shaft 50 there are
diametrically oppositely arranged openings 36, 37 which align with
the adjusting slits of adjusting bolts 53,54, 55,56. The adjusting
bolts 54,56 arranged diametrically opposite one another between the
prism holder 51 and the prism chair 52 carry out a horizontal
tilting of the prism chair 52 and thus of the rotatable prism 5 as
well as a height adjustment of the rotatable prism 5. The adjusting
bolts 53,55 which are likewise arranged diametrically opposite one
another and perpendicular to the prism are disposed between the
prism shaft 50 and the prism holder and cause a vertical tilting of
the rotatable prism 5. A cover 38 forms the outer closure of the
image-rotating optical system.
The invention is not restricted in design to the preferred
embodiments indicated above but a number of variations are possible
which make use of the solution illustrated in the drawings and
description even in basically different designs. Thus the drive
system for the image-rotating optical system illustrated in the
embodiment described above is also suitable for undertaking other
functions in optical systems of professional camera technology, for
example for swivel and incline movements in snorkel systems.
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